1. Field of the Invention
The present invention relates to techniques for adjusting a profile describing characteristics of a device.
2. Related Background Art
In a conventional color adjustment, a color adjustment is performed to a specific image and the thus adjusted image is then printed out. However, if the color adjustment is performed to the specific image, each time the image to be objective is changed, it is necessary that the color adjustment is redone every time.
On the other hand, if color matching is performed using a device profile (hereinafter, referred to as a profile) describing characteristics to each input/output device, it becomes possible to perform a color management consistency from input to output. In this method, even if the image to be objective is changed, there is no necessity that the color adjustment is redone. In FIG. 14, a conceptional view of general color matching is shown.
Input data of a color space dependent on a source device such as RGB or CMYK is converted into XYZ data or Lab data of a color space (PCS: Profile Connection Space) independent of a device by an input profile. Since a color out of a color reproduction range of an output device can not be represented by the output device, in order that all the colors are contained in the color reproduction range of the output device, a color space compression is performed to the input data converted into data of the color space independent of the device. And, after the color space compression is performed, the input data is converted from the color space independent of the device into the color space dependent on the output device such as RGB or CMYK.
However, even in color matching using such a profile, if accuracy of the used profile is not sufficient, ideal color matching results can not be obtained. Besides, even if the profile accuracy immediately after making is sufficient, device characteristics change by aging or the like, and if the profile is not adjusted, there is also a case that satisfactory color matching results can not be obtained.
Therefore, in case that sufficient profile accuracy can not be obtained, and in case that the profile goes not to match the device characteristics, the color adjustment of the profile becomes necessary.
A conventional color adjustment method of a profile is performed by a user performing the color adjustment with monitor-displaying the image to be objective, and the results are reflected on the profile.
However, since image quality evaluation of the color adjustment was by eye observation evaluation of the user, quality of the adjusted profile was influenced by experience and sensitivity of the user.
Besides, in the color adjustment by the eye observation evaluation on a monitor, it was hard to detect a different color (or color gamut) from an original image on a preview image, and if not experienced, it was difficult to master.